05
Nov
19

No confidence in new satellite tags fitted to brood meddled hen harriers

Last week we blogged about how the brood meddling project management team had agreed to fit a new, untested type of satellite tag to at least three of the five brood meddled hen harriers (see here).

This new tag was also fitted to other hen harrier chicks by Natural England this year. One of those chicks was called Rosie, who was reported as ‘missing’ on 17 September 2019 (here) only for her tag to re-start transmitting data three days later (here).

We blogged about the scientific and political stupidity of testing a new type of tag in the brood meddling trial, where understanding the fate of the brood meddled chicks is fundamental to assessing the trial’s ‘success’ or failure. It makes no sense whatsoever to do this – why not stick with the tags that you know, from several years worth of experience, have a 94% reliability rate on harriers? It’s been reported that three of the five brood meddled hen harriers ‘disappeared’ in September but because there is so little confidence in the reliability of the new tags nobody knows whether those birds have been illegally killed (like so many before them) or whether they’re actually fine and just carrying dodgy tags.

This afternoon we learned that at least one of those brood meddled hen harriers is actually ok and yes, it is clearly carrying a dodgy tag. This from Natural England on twitter:

So now we have no confidence whatsoever in these particular tags.

For the avoidance of doubt, that doesn’t mean that all satellite tags are unreliable, as undoubtedly the persecution deniers will try to claim. As we’ve blogged previously, there are many different tag models and the quality of both the tag and the data it produces can vary massively. There is constant communication between many researchers who deploy these tags as nobody in their right mind would want to buy a tag, let alone deploy it, if there was any hint of that particular model under-performing.

Which begs the question, again, why were these tags selected for the brood meddling trial?


16 Responses to “No confidence in new satellite tags fitted to brood meddled hen harriers”


  1. November 5, 2019 at 6:24 pm

    Why were these selected for the brood meddled birds?
    Perhaps the reason is the obvious one.
    Were they were known to be unreliable? YES
    Are those in denial about the persecution of Hen Harriers likely to bang on about the unreliability? YES
    Has the trial been designed to fail. I’ll let you make up your own mind, but mine is made up already. YES

    • November 5, 2019 at 6:27 pm

      Hi Alex,

      If the tags were untested on harriers in the UK (as we believe), then it can’t be argued that they were ‘known to be unreliable’.

      The point is, they weren’t tested so reliability was unknown prior to the brood meddling trial. There is a time and place to test new tags – the brood meddling trial shouldn’t have been it.

  2. 5 Chris Dobson
    November 5, 2019 at 6:51 pm

    As you pointed out, there were problems with the tags before the birds were released

  3. 6 sennen bottalack
    November 5, 2019 at 7:02 pm

    What a wonderfully Machiavellian scheme !
    Seeks to cast doubt on sat tags in all scenarios.
    Luckily, we are not so easily fooled, although the originators [ the criminal grouse industry aided and abetted by NE ] will hope that the general public will take the bait.
    Any independent analysis of this fiasco will will show just what a crock of sxxt it is.

    Keep up the pressure !

  4. 7 alancranston
    November 5, 2019 at 7:20 pm

    It strikes me that electronic devices rarely fail and then start working again (though obviously they do sometimes.) So in this case I wonder if the tags are operating ‘normally’ but in this practical application, some combination of satellite contact time, solar input, geography plus other stuff means that they can just fail to connect over a longish period, causing concern.

    None of which undermines the idiocy of using untested tags, it’s just that there may perhaps be faint hope for the other two birds.

  5. 8 Ernie Scales
    November 5, 2019 at 7:40 pm

    The deniers and naysayers are already active on the RSPB Scotland page.

  6. 9 sog
    November 5, 2019 at 10:34 pm

    One hopes that Supt Nick Lyall will have some questions to ask at the Raptor Group meeting.

  7. 10 Gerard
    November 6, 2019 at 2:49 am

    Interesting this. It actually looks like an attempt to muddy the water. FOI request for the minutes of the meetings where this tag was chosen over others?

  8. 11 Fight for Fairness
    November 6, 2019 at 9:58 am

    It is my view that the difficulty with the most common satellite tags used is that they are not designed to detect crime, just to plot the location of animals. They transmit until the battery runs out and then have to go off air to recharge, which may take several hours or perhaps more than a day. However, I have not heard reports about tags going off air for three days before. It does appear that the long time to recharge (which I suspect is what happened) is a fault in the equipment.

    There are other reasons why it is so important to move away from these tags to using tags currently in development which transmit continuously and use the much more accurate GPS technology, which can show position down to a few metres, rather than the 500 metres or so that current tags allow. At the moment I understand that these new type of tags are not small enough to be used on Harriers, but could be used on Eagles, which given the recent news about Sea Eagle disappearances, could be of great importance. As I have stated on RPUK before, I am happy to try and get funding for any project which will speed the availability of such devices for use on our birds of prey.

    • November 6, 2019 at 10:03 am

      Hi Fight for Fairness,

      Without going in to great detail, there are currently plenty of tags available using GPS technology to create accurate high resolution movement data and that don’t have to go offline to recharge.

      • 13 Fight for Fairness
        November 6, 2019 at 10:37 am

        Thanks for pointing this out. I cannot be more pleased to be wrong! We still need to know why, with Doppler effect tags not giving the evidence needed to fight crime, why they still seem to be used in applications where more accurate location data is vital? If it is just a money issue, I am sure that we can get over that, by sponsoring tags for example, or crowdfunding projects. As a (relatively) poor pensioner I have little money but lots of time and will be prepared to put in a lot of effort to stop the barbarity of bird of prey persecution and welcome the return of many Hen Harriers and Eagles to the Lammermuir hills near my home.

        • November 6, 2019 at 11:02 am

          Well because these tags are not being fitted to ‘fight crime’, as you astutely pointed out in your original comment. There are many research applications where the coarser scale data are useful but other applications where finer, high resolution data are required to answer the research questions being posed.

          The identification of wildlife crime hotspots (through the killing or suspicious disappearance of tagged raptors) has been an unintended by-product of this type of research.

        • 15 sog
          November 6, 2019 at 12:04 pm

          I’ve see the 500-m comment before. On the scale of grouse moors, it’s probably fit-for-purpose. If that kit hasn’t been superseded.

  9. 16 Paul V Irving
    November 6, 2019 at 10:18 am

    I’m not sure this is an attempt to muddy the water but do that it certainly will for those who want to do so. Personally I just think the whole thing was and is down to crass stupidity perhaps we should send them all dunces caps for Xmas.


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